With mixed transition-metal-complex, alkali-metal, or organic cations as structure-directing agents, a series of novel two-dimensional (2D) layered inorganic-organic hybrid iodoargentates, namely, Kx[TM(2,2-bipy)3]2Ag6I11 (TM = Mn (1), Fe (2), Co (3), Ni (4), Zn (5); x = 0.89-1) and [(Ni(2,2-bipy)3][H-2,2-bipy]Ag3I6 (6), have been solvothermally synthesized and structurally characterized. All the title compounds feature 2D microporous layers composed by [Ag3I7] secondary building units based on AgI4 tetrahedra. Differently, the [Ag3I7] trimers are directly interconnected via corner-sharing to form the 2D [Ag6I11](5-) layer in compounds 1-5, whereas two neighboring [Ag3I7] trimers are initially condensed into a hexameric [Ag6I12] ternary building unit as a new node, which further self-assembles, leading to the 2D [Ag6I10](4-) layer in compound 6. The UV-vis diffuse-reflectance measurements reveal that all the compounds possess proper semiconductor behaviors with tunable band gaps of 1.66-2.75 eV, which lead to highly efficient photocatalytic degradation activities over organic pollutants under visible light irradiation compared to that of N-dotted P25. Interestingly, all the samples feature distinct photodegradative speeds at the same reaction conditions, and compound 1 features the highest photocatalytic activity among the title phases. The luminescence properties, band structures, and thermal stabilities were also studied.
The emergence of drug-resistant bacteria severely challenges the antimicrobial agents and antibacterial strategy. Here, we demonstrate a novel, simple, and highly efficient combination therapy strategy by direct combinations of cationic conjugated polymers (CCPs) with polypeptide antibiotics against Gram-negative and Gram-positive bacteria based on a synergistic antibacterial effect. The combination therapy method enhances the antibacterial efficacy with a significantly reduced antibiotic dosage. Also, the highly efficient and synergistic killing of drug-resistant bacteria is realized. Using combinations of CCPs and antibiotics to show increased antibacterial activity, this strategy will provide a much wider scope of the discovery of efficient antibacterial systems than that of antibiotic-antibiotic combinations. The proposed combination therapy method provides a universal and powerful platform for the treatment of pathogens, in particular, the drug-resistant bacteria, and also opens a new way for the development of efficient antibacterial systems.
By using transitional metal (TM) complex cations as structure-directing agents (SDAs), a series of new hybrid cuprous halides have been solvothermally synthesized and structurally characterized. The title compounds feature abundant architectures ranging from one-dimensional (1D) chains to two-dimensional (2D) layers built from the self-condensation of [CuX4] tetrahedrons and/or [CuX3] triangles. The UV-vis diffuse-reflectance measurements reveal that the title compounds possesses semiconductor behaviors with smaller band gaps of 1.44-1.95 eV, and show highly efficient photocatalytic degradation activities over organic pollutant than N-doped P25 under visible light irradiation. 661x495mm (96 x 96 DPI)
AbstractBy using transitional metal (TM) complex cations as structure-directing agents (SDAs), a series of new hybrid cuprous halides with abundant architectures ranging from one-dimensional (1D) ribbons to two-dimensional (2D) layers have been solvothermally prepared and structurally characterized.Compounds [TM(2,2-bipy) 3 ]Cu 5 I 7 (TM = Fe (1), Co(2) and Ni (3)) feature 1D [Cu 5 I 7 ] 2-chains formed by the interconnection of [Cu 5 I 10 ] units via edge-sharing. In compounds [TM(2,2-bipy) 2 I] 2 Cu 7 I 9 (TM = Mn (4), Cu(5), Ru (6)), the [Cu 5 I 9 ] units and [Cu 2 I 6 ] dimers are alternately interlinked via edge-sharing to form the 1D [Cu 7 I 9 ] 2-chains. Compound [Cu(2,2-bipy) 2 I][(Me) 2 -2,2-bipy]Cu 8 I 11 (7) contains a new 1D [Cu 8 I 11 ] 3-chain composed of complex [Cu 8 I 13 ] units based on CuI 4 tetrahedra and CuI 3 triangles. Compound [Co(2,2-bipy) 3 ]Cu 5 Br 8 (8) features 1D [Cu 5 Br 8 ] 3-anionic chain built form the interconnection of [Cu 6 Br 10 ] units and linear [Cu 4 Br 8 ] tetramers. In compound K[Mn(2,2-bipy) 3 ] 2 Cu 6 I 11 (9), the [Cu 3 I 7 ] secondary building units (SBUs) are directly interconnected to form 2D [Cu 6 I 11 ] 5-layers, which are further interconnected by K + ions via weak K-I bonds to generate a 3D [K@Cu 6 I 11 ] 4-framework with 1D large channels occupied by [Mn(2,2-bipy) 3 ] 2+ complexes. The UV-vis diffusereflectance measurements reveal that the title compounds possess semiconductor behaviors with smaller band gaps of 1.44-1.95 eV, and samples 4, 5 and 9 show highly efficient photocatalytic degradation activities over organic pollutant than N-doped P25 under visible light irradiation.
(S)-2-Chloro-1-(3,4-difluorophenyl)ethanol
(1) is a vital chiral intermediate for the synthesis
of Ticagreloran effective treatment for acute coronary syndromes.
A ketoreductase (KRED) KR-01 in our KRED library was screened to transform
2-chloro-1-(3,4-difluorophenyl)ethanone (2) into the
chiral alcohol 1. During process optimization, the bioreduction
procedure was performed at a substrate concentration of 500 g/L, giving
a near 100% conversion with >99.9% ee. The product 1 was
directly obtained by extraction and can be used for the synthesis
of (1R,2R)-2-(3,4-difluorophenyl)cyclopropanecarboxylic
acid ethyl ester (3) with a yield of 98% and >99.9%
de,
greatly simplifying the original process operation and reducing the
safety risk. This process is green and environmentally sound with
high productivity of biocatalysis and a space–time yield of
145.8 mmol/L/h. It has an opportunity to be very useful in industrial
applications. Additional studies have indicated that KR-01 can also
be used to prepare (R)-1-(3,5-bis(trifluoromethyl)phenyl)ethanol
(4) with a substrate concentration of 500g/L.
Four new hybrid iodoargentates have been solvothermally prepared and structurally characterized. The title compounds possess semiconductor characterizations and efficient photocatalytic activities under visible light irradiation.
The irrational or
excessive use of antibiotics causes the emergence
of bacterial resistance, making antibiotics less effective or ineffective.
As the number of resistant antibiotics increases, it is crucial to
develop new strategies and innovative approaches to potentiate the
efficacy of existing antibiotics. In this paper, we report that some
existing antibiotics can produce reactive oxygen species (ROS) directly
under light irradiation. Thus, a novel antibacterial photodynamic
therapy (PDT) strategy is proposed by using existing antibiotics for
which the activities are potentiated via light-activation. This antibiotic-based
PDT strategy can achieve efficient bacteria killing with a low dosage
of antibiotics, indicating that bacterial killing can be enhanced
by the light-irradiated antibiotics. Moreover, the specific types
of ROS produced by different antibiotics under light irradiation were
studied for better elucidation of the antibacterial mechanism. The
findings can extend the application of existing antibiotics and provide
a promising strategy for treatment of bacterial infections and even
cancers.
Hollow mesoporous carbon submicrospheres (HMCNs) have been successfully synthesized via a facile silicaassisted sol−gel strategy, which were further treated with KOH or/and HNO 3 to obtain four adsorbents with different structures and surface properties for the removal of dibenzothiophene (DBT). KOH activation can effectively adjust the micro/ mesoporous structure by increasing the number of micropores, and HNO 3 oxidation can modify the surface properties by introducing oxygen-containing functional groups. HMCNs treated with KOH first and then HNO 3 are the best for DBT removal with the adsorption capacity of 33.20 mg S•g −1 , which is nearly 45% higher than that of activated carbon with the same treatment. Notably, the adsorption equilibrium can be achieved within only 5 min, much faster than active carbon owing to the existence of abundant mesopores favorable to the diffusion of DBT. The negative ΔG°from thermodynamics result suggests it is a favorable and spontaneous adsorption process.
The catalytic hydrogenation of petroleum resin (PR) is an efficient process to produce high-value-added hydrogenated PR with improved performance and wide applications. Herein, a hierarchical flower-like NiCu/SiO 2 bimetallic catalyst has been successfully prepared by reducing the hierarchically structured NiCu silicate precursor ((Ni,Cu) 3 Si 2 O 5 (OH) 4 ) and applied for PR hydrogenation. The generated bimetallic NiCu alloy nanoparticles are anchored on the surface of the intercrossed silica nanoplatelets, constructing a unique multilevel NiCu/SiO 2 superstructure. Moreover, the addition of Cu could not only lower the reduction temperature of Ni species but also provide electrons to Ni to form electron-rich active sites. The NiCu/SiO 2 bimetallic catalyst exhibited enhanced catalytic activity and stability for PR hydrogenation. The hydrogenation degrees for C 5 PR and C 9 PR could reach up to 94.9 and 96.3%, respectively, which are much higher than those catalyzed by the catalyst prepared via an impregnation method (85.9 and 88.7%). Such notably enhanced performances could be ascribed to the synergistic effect between Ni−Cu bimetals and the highly porous superstructure. Our findings provide guidance for the design and synthesis of efficient and stable bimetallic nanocatalysts for PR hydrogenation.
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